also known as: red onyx
Sardonyx is mentioned in the foundations of the coming New Jerusalem.
The foundation stones of the city wall were adorned with every kind of precious stone. The first foundation stone was jasper; the second, sapphire; the third, chalcedony; the fourth, emerald; the fifth, sardonyx; the sixth, sardius; the seventh, chrysolite; the eighth, beryl; the ninth, topaz; the tenth, chrysoprase; the eleventh, jacinth; the twelfth, amethyst. … —Revelation 21:19-21 LSB excerpt
a species of the carnelian combining the sard (shades of red) and the onyx, having three layers of opaque spots or stripes on a transparent red basis